Use of phosphoroustrislactams as compatibilizing agents for polyphenylene oxide/polyester blends

ABSTRACT

The invention relates to improved polymer material blends which include the compatibilizing agent, a compound of phosphoroustrislactams which is useful as a compatibilizing agent, between the polymer materials. An exemplary composition comprises one or more polyphenylene oxides, one or more polyesters and the compatibilizing agent comprising phosphoroustrislactams.

This application is a division of application Ser. No. 562,355, filedAug. 3, 1990.

BACKGROUND

1. Field of the Invention

The present invention relates to improving the properties of particularmolding compositions, particularly those comprising polyphenylene oxides(also known as polyphenylene ethers) and a polyester through the use ofa phosphoroustrislactam as a compatibilizing agent.

2. Description of the Prior Art

Engineered plastics enjoy widespread popularity for the production ofarticles through the use of molding or casting processes. Theseengineering plastics are frequently blends of two or more specificconstituents which feature specific properties, i.e., toughness,rigidity, chemical resistance, long-term hygrothermal dimensionalstability, dielectric strength, and the like. While such engineeringplastics comprising two or more specific constituents would optimallyexhibit the beneficial properties of each constituent, unfortunately, asis well known to the art, the formation of blended polymeric materialsare rarely attained which offer these desirable characteristics of theconstituents making up its composition, without simultaneously sufferingfrom some detrimental quality.

Poly(alkylene terepthalates) including poly(ethylene terepthalate), alsoknown to the art by its acronym "PET", and poly(butylene terepthalate),similarly referred to as "PBT" are aromatic polyesters which enjoyfrequent use where rigidity, ductility, high melting point and solventresistance, are required. This is known to the art to be due to therelatively high degree of crystallinity which polyalkyleneterephthalates, particularly PBT, exhibit subsequent to cooling from themelt. However, these materials are known have relatively low glasstransition temperatures, "T_(g) " and suffer heat distortion undermechanical loads at relatively low temperatures. Further, thesematerials are also known to suffer from a marked loss in their impactresistance subsequent to annealing or heat ageing, which may be due tosubsequent processing of the article during its production, or fromprolonged exposure to heat during its use. Blends of poly(phenyleneethers), which are also known to the art as poly(phenylene oxides) andwhich are commonly referred to as "PPE" or "PPO", and polyesters areexpected to have increased heat distorion temperatures due to the highglass transition temperature, (interchangeably referred to as T_(g)) ofthe PPE.

Polyphenylene ethers, also interchangeably referred to in the art as"polyphenylene oxides" are compounds known to exhibit good performancecharacteristics in elevated temperatures, or after heat ageing due tothe high glass transition temperatures, T_(g) which such materialstypically exhibit. Further, such materials also exhibit good ductilityand hydrolytic stability. Compositions comprising PPE and polyestershave been synthesized, and such compositions are described in PCTApplication PCT/US/01027 for "Polyphenylene Ether-Polyester Copolymers,Precursors Therefor, Compositions Containing Said Copolymers, AndMethods For Their Preparation" which describes a series offunctionalizing agents, preferably those selected from among; maleicacid and derivatives thereof, fumaric acid and trimellitic anhydride,which are useful in promoting bonding between the PPE phase andpolyester phase in the composition.

A further composition is that described in International ApplicationPCT/US86/01572 for "Solvent-Resistant, Compatible Blends ofPolyphenylene Ethers and Linear Polyesters" which describescompatibilized blends which include polyphenylene ether, polystyrene,poly(alkylene dicarboxylate), an elastomereic impact modifier and afurther polymer.

A further composition comprising PPE, and a thermoplastic polyesterblend containing a large proportion of polycarbonates which iscompatibilized through the use of a poly(phenylene) ether is describedin U.S. Pat. No. 4,927,881 issued on May 22, 1990.

A still further composition is that described in an application by thesame inventors as in the instant application for a U.S. Patent titled"Process for Preparing Graft and Block Copolymers of PolyphenyleneOxides and Polyesters and Copolymers Prepared by said Process" filed onDec. 4, 1989 and assigned Ser. No. 446,512. Therein is described acomposition where a tris(phenyl)phosphite is used as a compatabilizingagent for polyphenylene oxide and polyester resins.

Such methods provide useful molding compositions having good physicalproperties, but also undesirably produce free phenol during the reactionwhich is widely regarded as a toxin and requires particular care inorder to effect its removal.

The activity in this art, is merely one indication that there remains aneed for continued development, and further improved compositionscomprising PPE and polyesters. It is to this need, as well as otherneeds, that the present invention is addressed.

SUMMARY

In one aspect of the invention, there is provided an improvement inblends comprising one or more polyphenylene ethers, and one or morepolyesters which is achieved by the inclusion of a phosphoroustrislactamas a constituent used in forming the blend composition. Thephosphoroustrislactam acts as a compatibilizing agent between the PPEand the polyester and induces active coupling therebetween, and therebyproviding materials which exhibit improved physical characteristics thanthose provided in the art.

A further aspect of the invention is a method of producing articlescomprising improved blends of one or more polyphenylene ethers, and oneor more polyesters and at least one phosphoroustrislactam as acompatibilizing agent between the PPE and the polyester.

Further aspects of the invention not particularly recited here willbecome apparent upon a reading of the accompanying specification of thepreferred embodiments and the claims below.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Polyphenylene ethers suitable for use in the present invention are wellknown in the art as well as their methods of preparation. What is meantby the term "polyphenylene ether", (also interchangeably referred to as"PPE") is to include not only those compositions of unsubstitutedpolyphenylene ether, but additional is also to include polyphenyleneethers with various substituents. Further, this definition is meant toinclude PPE copolymers as well as graft copolymers and block copolymersof alkenyl aromatic compounds, especially vinyl aromatic compounds and apolyphenylene ether.

By way of illustration, and not by limitation, suitable phenol compoundsuseful for the derivation of PPE therefrom include those represented byformula [1] as follows: ##STR1## wherein each R is representative of amonovalent substituent selected from the group consisting of hydrogen,halogen, aromatic hydrocarbon, aliphatic hydrocarbon, as well ashydrocarbonoxy radicals which are free of a tertiary alpha carbon atomand halohydrocarbon and halohydrocarbonoxy radicals free of a tertiaryalphacarbon atom and which comprises as least two carbon atoms betweenthe halogen atom and the phenyl nucleus, and wherein at least one R ishydrogen.

Particular nonlimiting examples of the phenol compounds which arerepresented by the above formula include:

2,4-dimethyl-phenol,

2,5-dimethyl-phenol,

2,6-dimethyl-phenol,

2-methyl-6-phenyl-phenol,

2,6-diphenylphenol,

2,6-diethylphenol,

2-methyl-6-ethyl-phenol,

the ortho-, meta- and para-cresols,

as well as 2,3,5-trimethylphenol,

2,3,6-trimethylphenol

and 2,4,6-trimethylphenol.

Additionally, two or more phenol compounds may be used in combination toform copolymers.

By means of example and not by way of limitation, several suitablepolyphenylene ethers include:

poly(2-methyl-1,4-phenylene)ether,

poly(2,6-diethyl-1,4-phenylene)ether,

poly(2,6-dichloromethyl-1,4-phenylene)ether,

poly(2,3,5,6-tetramethylphenylene)ether,

poly(2,6-dichloro-1,4-phenylene)ether,

poly(2,6-dimethyl-1,4-phenylene)ether,

poly(2,6-dipropyl-1,4-phenylene)ether,

poly(2-ethyl-6-propyl-1,4-phenylene)ether,

poly(3-methyl-1,4-phenylene)ether,

poly(2,3,6-trimethyl-1,4-phenylene)ether,

poly(2-methyl-6,allyl-1,4-phenylene)ether,

poly(2,5-dimethyl-1,4-phenylene)ether,

poly(2,6-diphenyl-1,4-phenylene)ether, as well as other similarcompositions not specifically delineated here.

Further, as already has been mentioned, copolymers of the phenolcompounds are also contemplated.

Preferably, the polyphenylene ethers will have the formula according toformula [2]: ##STR2## wherein n has a value of 50 or in excess thereof,and R is consistent with the definition given above. By means of exampleand not by way of limitation, several polyphenylene ethers suitablyrepresented by the above formula include:

poly(2-ethyl-6-ethoxy-1,4-phenylene)ether,

poly(2-methoxy-6-ethoxy-phenylene)ether,

poly(2,6-dilauryl-1,4-phenylene)ether,

poly(2,6-dibromo-1,4-phenylene)ether,

poly(2,6-diphenyl-1,4-phenylene)ether,

poly(2,6-diethoxy-1,4-phenylene)ether,

poly(2-ethoxy-1,4-phenylene)ether,

poly(2,6-dimethoxy-1,4-phenylene)ether,

poly(2-methyl-6-phenyl-1,4-phenylene)ether,

poly(2,6-dichloro-1,4-phenylene)ether,

poly(2-chloro-1,4-phenylene)ether,

as well as other similar compositions not specifically delineated here.

Methods for the production of PPE are well known to the art, and by wayof example, phenols may be oxidized in the presence of an oxygencontaining gas and a catalyst which induces oxygen coupling with thephenol. Examples of such suitable catalysts include those comprising acupric salt, a tertiary amine, and an alkali metal hydroxide, or onecomprising a manganese salt and an alcoholate, or a manganese salt and aphenolate. The preferred PPEs are those comprising a lower alkyl groupsubstitution in the positions described as R in formula [2] above, andwhich include hydroxyl terminal groups in their structure.

The poly(phenylene ether)s used are described as having intrinsicviscosities of 0.51, 0.45, and 0.30 respectively, melt viscosities at300 deg. C. of 63180, 8900 and 285 respectively, Wt.Avg.Mol.Wt. of80900, 64400 and 34800 and No.Avg.Mol.Wt. of 12600, 10400 and 4800respectively. These materials exhibit phenolic hydroxyl concentrationsof 0.06, 0.76 and 0.22 meq/g as determined by titration of theseconstituents with tetra (n-butyl) ammonium hydroxide.

Polyesters which find use with the present invention includethermoplastic polyester resins which are characterized in exhibiting anintrinsic viscosity of 0.3 to 1.0 dl/g when measured in a 60/40 weightpercent mixture of phenol/tetrachlorathene and which further includecarboxyl or hydroxyl terminal end groups. Optionally, the end groups maybe partially capped, such as throught the use of a monoester.

Thermoplastic polyester resins which are preferred for use inconjunction with the instant invention are poly(alkylene terephthalate)resins, including poly(ethylene terephthalate), poly(butyleneterephthalate), poly(tetramethylene terephthalate), poly(aryleneterephthalate) and copolymers and/or mixtures thereof. As is known tothe art, these polyester resins may be obtained through thepolycondensation of terephthalic acid, or a lower alkyl ester thereof,and an alkylene diol. By way of example, polyethylene terephthalate orpolybutylene terephthalate may be produced by polycondensation ofdimethyl terephthalate and ethylene glycol, or 1,4-butane diol after anester interchange reaction.

Of these, PET is the preferred polyester as it exhibits a high meltingpoint, good crystallinity and good solvent resistance. The amount ofpolyester and PPE may vary widely, and in general may vary in that theamount of each of these constituents may be present so to comprisebetween 10 percent to approximately 90 percent of a composition inaccording with the teaching of the instant invention, which necessitatesonly that the final composition be partially compatibilized by the useof the phosphoroustrislactams which are incorporated into thecompositions. Preferably, the polyester should comprise between about25% and 75% of a composition, and more preferably, the polyester shouldcomprise between 25% and 60% of the composition. Similarly, thepolyphenylene ether should comprise between about 25% and 75% of acomposition, and more preferably, the polyphenylene ether shouldcomprise between 25% and 60% of the composition in accordance with theteachings of the present invention.

The phosphoroustrislactams which find use in the present invention isparticularly described in a pending U.S. patent application for"PHOSPHOROUSTRISLACTAMS AND METHODS FOR THEIR PRODUCTION", Ser. No.542,942 filed on June 25, 1991 of the same inventors and assigned to thesame assignee as the instant application, the complete contents of whichare herein incorporated by reference. The phosphoroustrislactams may bedescribed as compounds in accordance with formula [3], below ##STR3## oralternately, in accordance with formula [4]. ##STR4## where X representsa chain of CH₂ monomer repeat units of at least 1 and including up to 11CH₂ monomer repeat units.

The phosphoroustrislactams are utilized as reactive intermediates whichare capable of compatibilizing PPE and the polyester in the compositioninducing what is believed to be a coupling reaction between the hydroxylend group of the PPE with the carboxyl end group of the polyester whichresults in a block or graft copolymer. Under ideal circumstances,equimolar amounts of hydroxyl terminal groups of a poly(phenylene ether)is reacted with the carboxyl terminal group of a polyester in thepresence of a tri(lactamyl)phosphite. The reaction liberates asbyproducts equimolar amounts of a caprolactam and phosphorous acidderivatives. Due to the relatively inert nature of these byproducts, thereacted PPE and polyester remains stable, and the remaining water,caprolactam and phosphorous acid derivatives may be removed byconventional methods. One beneficial feature of this reaction is thatnone of the byproducts of the coupling reaction exhibit presently knowntoxic characteristics which is in contrast to the use of a tri(phenylphosphite) which forms phenol comprising compounds as a byproducts ofits reaction. Further, it has been found that unlike the use of atri(phenyl phosphite) which requires that vacuum conditions be used soto remove the produced phenol comprising compounds in order to eliminatethe reversibility of the compatibilizing reaction, the use of thephosphoroustrislactams as a compatibilizing agent is not reversibleunder usual processing conditions.

Various optional ingredients may also be incorporated as constituentsinto blends in accordance with the present invention in order to impartfurther specific properties thereto. The use of one such additive, whichis a constituent preferentially utilized, is a material which is used todecrease the crystallinity of the polyester component. Examples of suchmaterials include homopolymers and/or copolymers of polycarbonates andpolyestercarbonates. Examples of polycarbonate containing polymers andpolycarbonates, and polyestercarbonates include but are not limited topoly(methane bis(4-phenyl)carbonate), poly(1,1-ethanebis(4-phenyl)carbonate), poly(2,2-propane bis(4-phenyl)carbonate),poly(1,1-butane bis(4-phenyl)carbonate, poly(2,2-butanebis(4-phenyl)carbonate, poly(1,1-(1-phenylethane)bis(4-phenyl)carbonate), poly(dipenylmethane bis(4-phenyl)carbonate)which can be obtained from commercial sources or prepared by knowntechniques. Examples of such commercially available materials includethe family of polycarbonate materials marketed by the General ElectricCo. under the trade name Lexan®. Further examples of useful polyestercarbonates and methods for their production are described in U.S. Pat.Nos. 4,156,069, 4,386,196 and 4,612,362.

Such carbonate containing polymers function in reduction of thecrystallinity of the polyester component. In accordance with theteaching of the instant invention, any amount of such carbonatecontaining polymers which is found to satisfactorally reduce thecrystallinity of the polyester component may be used. However, theamount of carbonate containing polymer added is usually from about 5% toabout 40% by weight based on the total weight of the polyester, and ispreferably from about 5% to about 35% by weight of the polyester, andmost preferably between 5% to about 25% by weight of the polyester.

In preferred embodiments of the invention, a polymer exhibitingelastomeric properties may be included where the inclusion of such apolymer provides a beneficial effect upon the impact resistance ofmaterials formed from such a blend. Throughout this specification andthe claims, the term "functionalized elastomer" is meant to beunderstood as the polymer exhibiting elastmeric properties and provind abenficial effect upon the impact resistance of materials as describedhereinafter. Such an elastomeric polymer is defined as having an ASTMD-638 tensile modulus of less than about 40,000 psi (276 MPa), andpreferably less than about 20,000 psi (138 MPa). Examples of suchelastomeric polymers may be block, graft or random copolymers, and canbe made of reactive monomers which comprise part of the polymer chains,or grafted, or as branches of the polymer. Some examples of suchreactive monomers include dienes, unsaturated carboxylic acids, as wellas derivaties thereof, including esters and anhydrides as well asunsaturated epoxide moiety containing constituents. By way ofillustration, but not by way of limitation, examples of such usefulelstomeric polymers include α-olefin containing copolymers, especiallyethylene copolymers, copolymers containing acrylic acid salts, known tothe art as "acrylic acid ionomers" which include by way of illustrationetylene/methacrylic acid neutralized with sodium, ethylene/maleicanhydride, ethylene/ethyl acrylate, ethylene/glycidyl methacrylate,ethylene/methyl methacrylate and the like. Further examples ofelastomeric polymers include natural rubber, nitrile rubber,polyacrylates, butadiene polymers, isobutylene/isoprene copolymers,styrene/ethylene/propylene/diene copolymers, acrylonitrile/styrene/dienecopolymers, ethylene/styrene/diene copolymers, butadiene/styrenecopolymers, styrene/butadiene/styrene copolymers,acrylonitrile/butadiene/styrene copolymers, acrylic core shell rubberssuch as:

methyl methacrylate/butadiene/styrene graft copolymers,

polyalkylene oxide elastomers,

poly(dimethyl siloxane) rubbers, and the like, poly(chloroprene),acrylonitrile/butadiene copolymers, poly(isobutylene),isobutylene/butadiene copolymers, ethylene/propylene copolymers,polyneoprene, ethylene/propylene/butadiene copolymers, as well as whollyor partially hydrogenated, oxidized or carboxylated derivatives. Usefulelastomeric polymers can include monomeric units derived from aromaticvinyl monomers, olefins, acrylic acid, methacrylic acid, and theirderivatives. These mateirals may be obtained from commercial sources orproduced through techniques known to the art. Further examples of usefulelastomeric polymers and methods of their production are described inU.S. Pat. No. 4,315,086 and 4,175,358.

Preferred elastomeric polymers (also known to the art as "rubbers" or"rubbery polymers") are carboxylated or epoxide moiety containingelastomers, including those which are reaction products of rubber withanhydrides, and include maleic anhydrides; reaction products of rubberwith glycidyl methacrylates, and subsequent oxidation as may be effectedby the use of a permanganate; grafting reactions of the double bonds ofunsaturated monomers having pendant carboxylic acid functions such asacrylic acid, methacrylic acid, and the like. Particularly preferredrubbers include maleated rubbers, especially where the rubbers aresimple tri-block copolymers of the "A-B-A" structure, or are multiblockcopolymers of the "[AB]_(n) " linear or radial type, where "n" is anyinteger between 2 and 10 inclusive, "A" is representative of a blockderived from a polyvinylaromatic monomer such as styrene or vinyltoluene, and "B" is a block derived from a conjugated diene monomer aswell as hydrogenated derivatives thereof. Many of these elastomers arecommercially available under the trade name Kraton® from Shell ChemicalCo.

The elastomeric material functions to improve the impact resistance ofblends according to the invention, and the amount of elastomericmaterial added may be any amount which provides such an impactresistance improvement ot the blend. Based on the weight of thepolyester and the polyphenylene ether, the elastomeric material ispresent in an amount of between 2.5% and 25%, preferably in an amountbetween 3% and 18% inclusive, and most preferably form about 5% and 15%by weight on the aforementioned basis.

Other optional constituents which may be incorporated into the blendsaccording to the instant invention include such materials as fillers,impact modifiers, dyes, colorants, pigments, plasticizers, mold releaseagents, fire retardants, drip retardants, antioxidants, UV stabilizingagents, mold release agents, colorants, antistatic agents, nucleatingagents, thermal stabilizing agents, and the like. These optionalconstituents may be added to the mixture at any appropriate time duringthe production of the blend, and as they are well known to the art, arenot here described with particularity. All of these optionalconstituents are commercially available.

The compositions according to the instant invention may be made by anytechnique or process, presently known yet to be developed which willeffect an intimate blending of the constituents of the compositions,particularly the PPE, polyester and the phosphoroustrislactam. By way ofexample, such useful methods include formation of a solution in whichthe constituents are dissolved, suspended or dispersed in a suitablesolvent, after which the solvent is removed from the resultant blendcomposition by conventional processes in order to form compositions inaccordance with the teachings of the instant invention. An alternativetechnique is by the dry-blending the constituents in a dry particulateform, such as powders, pellets, flakes, prills or the like, and thenheated to a temperature equal to or greater than the melting point ofeither the PPE or the polyester. A further variation on this techniquewhich may be utilized where all of the desired constituents are notavailable in powder form, is an additional process steps of mixing anyliquid constituents or constituents in liquid form, subsequent to dryblending of the constituents, and thoroughly mixing the constituents, aswell as removal of excess liquids during processing by well knowntechniques.

During production of compositions according to the instant invention, itis recognized that acceptable temperatures used in heating theconstituents may vary over a wide range, and is dependent upon theconstitution of the any particular blend composition. Preferably, thetemperature should be at least as high as the melting point of thepolyester and the PPE but at the same time, should not be as high as thedegradation temperatures of either the PPE or the polyester. Inparticularly preferred embodiments, the temperature is such that thepolyester and PPE will be retained in a molten state sufficiently longto allow for the phosphoroustrislactam to react with either thepolyester or PPE and form a block or graft copolymer therewith.

The heating of the constituents may be carried out in any manner wherebythe temperature constraints outlined above are achieved. In onecontemplated method, the heating step is carried out at a temperaturewhich is equal to or greater than the melting point of the desiredresultant composition. In an alternative method, the constituents areheated so that the temperature is increased as a function of time overthe course of any heating process to cause the melting of constituentsin the manner described in this specification, and to maintain thismixture in a molten state. Other methods not particularly describedhere, but which may be utilized in forming compositions according to thepresent invention are contemplated and considered within the scope ofthe invention.

Pressures are not contemplated to have any critical effect, and can bewidely varied without adversely effecting the process of forming theinventive compositions. consequently, heating can be conducted atpressures below, at, or above atmospheric pressure. In preferredembodiments, at least a portion of the heating step is carried out at areduced pressure so to allow the removal of any volatile constituents orby-products. The production of compositions may be conducted undernormal atmospheric conditions, or in the absence of air. Alternately,the production of compositions may be conducted in a controlledatmosphere, such as in the presence of an inert gas, such as argon,nitrogen, carbon dioxide, or other inert gas.

The time needed to react the constituents may vary over a wide range,and is recognized to be a factor of such effects as the polyester andPPE selected, additional constituents selected, the concentration ofeach of the constituents forming the composition, the temperatures to beused as well as the type of heating step used, as well as the type ofreaction vessel and the manner of forming the composition. These arefactors which are known in the art as effecting reaction times. In mostinstances, the reaction time will vary between from about 5 seconds upto about 25 hours, preferably, the reaction times vary between about 30seconds to about 1 hour.

Preferably, the process of forming compositions in accordance with theinstant invention includes a process step of removing any by-products ofthe reaction, as well as unreacted phosphite compounds. The methods usedmay be any conventional means which does not adversely effect thecomposition formed. In preferred embodiments, all or part of theunreacted phosphite compounds are removed as it is believed that suchremoval enhances the effectiveness of the grafting process and improvesthe mechanical and other properites of the blend. Ideally, a compositionwhere all of the unreacted phosphite compounds are removed forms themost preferred embodiment of the invention, however it is concurrentlyrecognized that complete removal is not always possible. The removal ofanother by product, water, also forms a preferred embodiment of theinvention and its removal by any techniques not detrimental to theproperties of the blend may be used. Preferably, such techniques includeformation of the blend under vacuum conditions or under reducedpressures, during any heating step.

The formation of compositions may be carried out in a batchwise fashion,or alternatively in a continuous fashion. In the case of the former, areaction vessel suitable to contain the constituents and to providesuitable reaction conditions, e.g. heat, temperature, adequate mixing ofthe constituents, atmosphere may be used, and such vessels includecommon laboratory glassware and flasks, Banbury mixers, and the like. Inthe case of the latter, an extruder of the single or multiple screwvariety having at least one reaction zone may be utilized, as well asextruders having multiple zones, both in a series arrangement or in aparallel arrangement.

The compositions of the instant invention are suitable for the formationof articles by subsequent molding or forming techniques, including butnot limited to compression, injection, extrusion, as well as othertechniques not particularly recited here, but which are nonethelessuseful in forming formed articles therefrom.

The compositions of the instant invention are useful in all applicationswherein polyesters and polyphenylene ethers (polyphenylene oxides) maybe used; however, one distinguishing feature of the compositions of thepresent invention is that in their formation no phenols or phenoliccompounds are formed or released.

The foregoing invention will be more apparent by reference to specificembodiments which are representative of the invention. It is nonethelessto be understood that the particular embodiments described herein areprovided for the purpose of illustration, and not be means oflimitation, and that it is to be further understood that the presentinvention may be practiced in a manner which is not exemplified hereinwithout departing from its scope.

EXAMPLES

In the following embodiments of the invention, it is to be understoodthat in the description of any composition, all percentages associatedwith a constituent used to form a composition are to be understood as tobe "percentage by weight" of the particular constituent relative to thecomposition of which it forms a part. Exceptions to this convention willbe particularly noted.

For each of the examples, the poly(ethylene terephthalate) usedexhibited an intrinsic viscosity of 0.3 to 1.0 dl/g when measured in a60/40 weight percent mixture of phenol/tetrachlorathene. Thepoly(phenylene ether)s, or PPEs used were used as described below, andthe phosphorous triscaprolactam used was the reaction product ofcaprolactam and phosphorous trichloride.

EXAMPLES 1-4

For forming Examples 1 through 4, a mixture of 48.5 parts of PET, and48.5 parts of PPE having, in examples 1 and 3 having an intrinsicviscosity of 0.36 as measured in chloroform, and in examples 2 and 4,having an intrinsic viscosity of 0.46 also as measured in chloroform,were tumble blended together in a sealed container with 3 parts ofphosphorous triscaprolactam. Afterwards, each of the mixtures weresupplied to the feed hopper placed at the throat of a Killion 1 inchsingle screw extruder. The extruder barrel has a length to diameterratio of 30 to 1, and the zones of the barrel were heated to thefollowing temperatures: zone 1, 400 deg. F., zone 2, 500 deg. F., zone3, 510 deg. F., zone 4, between 520-550 deg. F. The extruder included aninjection port located 15.5 inches from the throat of the screw andimmediately preceeding a high-compression zone, which zone has a lengthof 8 inches, and the extruder also included a vacuum port located nearthe die. The first exit die was maintained at a temperature of 530degrees F., and the second die was maintained at a temperature ofbetween 480-510 deg. F. The extruder was outfitted with a 2 stageMaddock screw, and throughout the extrusion the rotational speed of thescrew was maintained at a constant of 50 RPM. The extrudate exiting thedie was in the form of strands having a diameter of 1/4 inch, and werequickly passed into a water bath to quench and cool the strands. Themass output of the extruder was determined to be 39 grams/minute. Thestrands were subsequently pelletized to form a feed stock useful forinjection molding. The extrudate so formed was noted to be amber incolor. A portion of the pellets so formed was removed, ground to form afine powder and exhaustively extracted in chloroform in order to removeas much as possible of the unreacted PPE remaining in the extrudate. Theresulting powder was dried in a vacuum. The amount of the extractablePPE which was determined for each of the compositions provided anindicator of the relative amount of reacted PPE resulting from theextrusion process.

For the production of a film, the respective compositions which wereground in a mill through a 2 mm screen and dried overnight at 110 deg.C., and afterwards were placed on the Teflon® coated side of a sheet ofaluminum foil of thickness 0.003 inch. A preheated steel plate atapproximately 280 deg. C. and having dimensions of 8 inches by 8 incheswere used to underlay the non-coated side of the aluminum foil sheetbearing the powder was leveled and then a similiar second piece ofTeflon® coated aluminum foil was placed on the powder so that the powderwas contained between the two Teflon® faces of the two aluminum foilsheets. A second preheated steel plate of like dimensions and atapproximately 280 deg. C. was layered in register on the non-Teflon®coated side of the second sheet of aluminum foil to form a sandwichstructure after which the sandwiched structure was inserted into theheated Wabash molding press which throughout the molding operation wasmaintained at 280 deg. C. After 60 seconds of contact pressure, that isto say 0 psig, the pressure was gradually and continuously increased to5 tons over a period of 30 seconds in order to improve the flow of thepowder. Afterwards, at 90 seconds after the original insertion of thesandwiched structure, the pressure was increased to 50 tons, and theremaintained for 90 seconds. Afterwards, the entire assembly was removedand transferred to cooling platens and there maintained under a pressureof 50 tons for a period of between 7-8 minutes. Afterwards, thesandwiched structure was disassembled, and the film structure formed bythe compression operation was recovered.

For performing physical testing of the material, the compression moldedformed structures noted above were cut into "Type" 4 bars, which weresubsequently tested to determine their tensile properties according toASTM-D 638, and the results are summarized on Table 1 below.

                  TABLE 1                                                         ______________________________________                                        Example:     1       2         3     4                                        ______________________________________                                        PPE, I.V.    0.36    0.46      0.36  0.46                                     in dl/g                                                                       Tensile      5.8     4.7       5.2   5.1                                      Strength, kpsi.                                                               Tensile      406     397       385   388                                      Modulus, kpsi.                                                                Elongation, %                                                                              1.6     1.3       1.4   1.4                                      % extractable                                                                              39      35        30    28                                       PPE                                                                           % reacted    22      30        40    44                                       Vacuum       no      no        yes   yes                                      ______________________________________                                    

COMPARATIVE EXAMPLES C1-C2

Samples consisting of a blend of PPE, PET and no phosphoroustriscaprolactam were produced in accordance with the method outlined forforming examples 1 and 2. The compositions consisted of 50 parts PET and50 parts PPE, having for example C1 an intrinsic viscosity of 0.36, andfor example C2 an intrinsic viscosity of 0.46 as measured in chloroform.The constituents were supplied in the form of granular powders whichwere subsequently tumble blended together and subsequently extruded andthe extrudate compression molded into "Type 4" tensile bars suitable foruse in subsequent physical testing. The results are summarized on Table2 below.

                  TABLE 2                                                         ______________________________________                                        Example:         C1      C2                                                   ______________________________________                                        PPE, I.V.        0.36    0.46                                                 in dl/g                                                                       Tensile          3.3     3.1                                                  Strength, kpsi.                                                               Tensile          366     329                                                  Modulus, kpsi.                                                                Elongation, %    1.5     1.1                                                  % extractable    49      45                                                   PPE                                                                           % reacted        2       9                                                    Vacuum           no      no                                                   ______________________________________                                    

An evaluation of the comparative examples C1 and C2 with those ofexamples 1-4 tends to show that the use of the phosphoroustriscaprolactam acts to significantly improve the tensile strength ofmolding compositions comprising PPE and polyesters, particularly blendsof PPE and poly(ethylene terephthalate). As has been described before,this is attributed to the effects of compatibilization which areachieved by the use of the phosphorous triscaprolactam. Modestimprovements in the tensile modulus of blends formed utilizingphosphorous triscaprolactam are also indicated by the physical testresult data. Further, comparisons of the percentages of extractable PPEare indicative of the successful reactivity of the PPE in eachcomposition.

EXAMPLE 5

A composition comprising 38.5% of a polyphenylene ether having thecharacteristics of; Wt.Avg.Mol.Wt. (Mw) of 34800, No.Avg.Mol.Wt. (Mn) of4800, an intrinsic viscosity (IV) of 0.30, 38.5% of a poly(ethyleneterephthalate) having an intrinsic viscosity of 0.7, 10% of apolycarbonate resin which is commercially available from the GeneralElectric Co. under the designation Lexan® 101, 10% of a Kraton® rubber,an elastomeric constitutent which is commercially available from ShellChemical Co. under the trade designation "K-FG 1901X" and 3% of aphosphorous triscaprolactam was provided to the Killion 1 inch extruderand processed to form strands under the conditions of, and in the mannerused to form the articles according to Examples 1-4 recited above. Theextrudate was injection molded to form Type 2 tensile test bars inaccordance with ASTM D-638 requirements and physical testing yielded thefollowing results: repeated notched Izod test of 1.4 ft-lb/in., atensile modulus of 259 kpsi, a tensile strength of 6.1 kpsi, and anelongation of 23% at break.

COMPARATIVE EXAMPLE C3

Similar to the composition according to that recited as example 5 above,a composition comprising 38.5% of a polyphenylene ether having thecharacteristics of; Wt.Avg.Mol.Wt. (Mw) of 34800, No.Avg.Mol.Wt. (Mn) of4800, an intrinsic viscosity (IV) of 0.30, 38.5% of a poly(ethyleneterephthalate) having an intrinsic viscosity of 0.7, 10% of apolycarbonate resin which is commercially available from the GeneralElectric Co. under the designation Lexan® 101, 10% of a Kraton® as theelastomeric constituent from Shell Chemical and marketed under the tradedesignation "K-FG 1901X" and 3% of a triphenyl phosphite was processedusing a Killion 1 inch extruder to form strands under the conditions of,and in the manner used to form the products according to Examples 1-5recited above, the description of which is herein incorporated byreference. In like fashion, the extrudate was afterwards injectionmolded to form test bars in accordance with ASTM D-638 specificationsand physical testing yielded the following results: repeated notchedIzod test of 1.2 ft-lb/in., a tensile strength of 5.6 kpsi, and anelongation of 15% at break.

EXAMPLE 6

A blend of 49 parts by weight of a poly(phenylene ether) having anintrinsic viscosity of 0.36 as measured in chloroform, 49 parts byweight of poly(ethylene terephthalate) were tumble blended together in asealed container with 2 parts by weight of phosphorous triscaprolactam.Afterwards, each of the mixtures were supplied to the feed hopper placedat the throat of a Killion 1 inch single screw extruder outfitted with atwo-stage Maddox screw. The extruder barrel had a length to diameterratio of 30 to 1, and the zones of the barrel were heated to thefollowing temperatures: zone 1, 500-480 deg. F., zone 2, 480 deg. F.,zone 3, 500 deg. F., zone 4, between 500-520 deg. F. The extruderincluded an injection port located 15.5 inches from the throat of thescrew and immediately preceeding a high-compression zone, which zone hasa length of 8 inches, and the extruder also included a vacuum port nearthe die. The vacuum port was operated to draw a vacuum approaching 0 mmof mercury. The first exit die was maintained at a temperature of 520degrees F., and the second die was maintained at a temperature ofbetween 470-540 deg. F. The extruder was outfitted with a 2 stageMaddock screw, and throughout the extrusion the rotational speed of thescrew was maintained at a constant of 52 RPM, and the motor drew 5.0amperes of current to maintain a througput rate of 22 grams per minuteof extrudate. The extrudate exiting the die was in the form of strandshaving a diameter of 1/4 inch, and were quickly passed into a water bathto quench and cool the strands. The strands were subsequently pelletizedto form a feed stock useful for injection molding. The extrudate soformed was noted to be amber in color. A portion of the pellets soformed were removed, ground to form a fine powder and exhaustivelyextracted in chloroform in order to remove as much as possible of theunreacted PPE remaining in the extrudate and to determine the amount ofextractable PPE in the pelletized extrudate, which was then dried in avacuum.

The pelletized extrudate was afterwards injection molded to form testbars in accordance with ASTM D-638 specifications. The extruder used wasan Arburg Injection molding machine, which was maintained to have a melttemperature of 180 deg. F., and which was set to have the followingbarrel temperatures: First barrel temperature, 285 deg. C., secondbarrel temperature, 285 deg. C., third barrel temperature, 280 deg. C.The screw speed was set at 200, with the screw motor set at 18.0 Theboost pressure was 1100 psi, the holding pressure 400 psi. For themolding operation, a shot size of 7 lbs was used, and the followingtimes were used: injection time of 0.06 sec, a holding time of 15.0 sec,a cooling time of 10.0 seconds, amd a mold open time of 2.5 sec. Thesampled molded were noted to need no additional mold release agents fortheir removal, showed no warpage on cooling and evidenced nodelamination. The physical property testing yielded the results outlinedon Table 3 below.

EXAMPLE C4

A blend consisting of 50 parts by weight of a poly(phenylene ether)having an intrinsic viscosity of 0.36 as measured in chloroform, and 50parts by weight of poly(ethylene terephthalate) were tumble blendedtogether in a sealed container. The sample contained no phosphoroustriscaprolactam in its composition. Subsequently, the blend wasextruded, pelletized and injection molded in the manner used to form thecomposition of Example 6 above and subsequently subjected to testing. Ina like manner a portion of the extruded pellets were ground andexhaustively extracted with chloroform. The results of the testing areoutlined on Table 3 below.

EXAMPLE C5

A blend based on the final composition weight percentages consisting of48.5 parts by weight of a poly(phenylene ether) having an intrinsicviscosity of 0.36 as measured in chloroform, and 48.5 parts by weight ofpoly(ethylene terephthalate) were tumble blended together in a sealedcontainer. Subsequently, using the Killion 1 inch single screw extruderused Examples 1-4, the blend was extruded and during the extrusion, 3parts by weight of triphenylphosphite was injected via the liquidinjection port. During the extrusion, the vacuum port of the extruderwas maintained at a vacuum of approxiamtely 0 mm of mercury in order todraw off any phenols which were formed during the extrusion process. Theextrudate was pelletized and subsequently injection molded in the mannerused to form the composition of Example 6 above and subsequentlysubjected to testing. In a like manner a portion of the extruded pelletswere ground and exhaustively extracted with chloroform. The results ofthe testing are outlined on Table 3 below.

EXAMPLE 7

A blend composition consisting of 49 parts by weight of a preblendedmixture formed by coextruding a blend of PPE and Kraton® FG 1901x(having a ratio of PPE: Kraton® of 80:20), 10 parts by weight of apoly(carbonate) (Lexan® 101), 39 parts by weight of poly(ethyleneterephthalate) and 2 parts by weight of phosphorous triscaprolactam weresupplied to the feed hopper placed at the throat of a Killion 1 inchsingle screw extruder outfitted with a two-stage Maddox screw asdescribed in conjunction with Example 6. The zones of the barrel wereheated to the following temperatures: zone 1, 500-460 deg. F., zone 2,480 deg. F., zone 3, 500 deg. F., zone 4, between 500-520 deg. F. Theextruder included an injection port located 15.5 inches from the throatof the screw and immediately preceeding a high-compression zone, whichzone has a length of 8 inches, and the extruder also included a vacuumport near the die. The vacuum port was operated to draw a vacuumapproaching 0 mm of mercury. The first exit die was maintained at atemperature of 520 degrees F., and the second die was maintained at atemperature of between 420-540 deg. F. The 2 stage Maddock screw wasmaintained at a rotational speed of 52 RPM, and the motor drew 4.5amperes of current to maintain a througput rate of 50 grams per minuteof extrudate. The extrudate exiting the die was in the form of strandshaving a diameter of 1/4 inch, and were quickly passed into a water bathto quench and cool the strands. The strands were subsequently pelletizedto form a feed stock useful for injection molding. The extrudate soformed was noted to be amber in color. A portion of the pellets wereremoved, ground to form a fine powder and exhaustively extracted inchloroform in order to remove as much as possible of the unreacted PPEremaining in the extrudate and to determine the amount of extractablePPE in the pelletized extrudate, which was then dried in a vacuum.

The pelletized extrudate was afterwards injection molded to form Type 2test bars in accordance with ASTM D-638 specifications in the generalmanner outlined in Example 6 above, and afterwards the samples so formedwere subjected to physical testing. The results are outlined on Table 3below.

EXAMPLE C6

The composition according to Example 7 was replicated with themodification that the phosphorous triscaprolactam was not included inthe composition. In the same manner, the extrudate was pelletized andmolded into Type 2 test bars and subsequently tested. The results areincluded in Table 3 below.

                  TABLE 3                                                         ______________________________________                                        Example:   6       C4       C5    7      C6                                   ______________________________________                                        PPE, i.v.  0.36    0.36     0.36  0.36   0.36                                 Extractable                                                                              --      50       39    --     --                                   PPE, %                                                                        % reacted  --      --       26    --     --                                   Tensile Str.                                                                             9.6     7.0      8.9   6.7    6.4                                  (kpsi)                                                                        Tensile    333     --       --    247    --                                   Modulus,                                                                      (kpsi)                                                                        Flexural   --      349      352   --     380                                  Modulus,                                                                      (kpsi)                                                                        Elongation, %                                                                            3.8     2        3     36.6   6                                    Vacuum     yes     yes      yes   yes    yes                                  ______________________________________                                    

It will be appreciated that the instant specifications and examples setforth herein are by way of illustration and not limitation, and thatvarious modifications and changes may be made without departing from thespirit and scope of the present invention; the limitations of the use ofthe invention are imposed only by the appendant claims.

What we claim is:
 1. A composition comprising:a polycarbonate; apoly(phenylene ether); a polyester; and a phosphoroustrislactam.
 2. Acomposition comprising:a poly(phenylene ether); a polyester; aphosphoroustrislactam; and a functionalized elastomer.
 3. Thecomposition according to claim 2 wherein the poly(phenylene ether) is aderivative of a phenol compound having the formula ##STR5## wherein eachR is representative of a monovalent substituent selected from the groupconsisting of hydrogen, halogen, aromatic hydrocarbon, aliphatichydrocarbon, as well as hydrocarbonoxy radicals which are free of atertiary alpha carbon atom and a halohydrocarbon and halohydrocarbonoxyradicals free of a tertiary alpha-carbon atom and which comprises atleast two carbon atoms between the halogen atom and the phenyl nucleus,and wherein at least one R is hydrogen.
 4. The composition according toclaim 3 wherein two or more phenol compounds are utilized to derive thepoly(phenylene ether).
 5. The composition according to claim 3 whereinthe poly(phenylene ether) is at least one poly(phenylene ether) havingthe formula: ##STR6## wherein n has a value of 50 or in excess thereof,and R is representative of a monovalent substituent selected from thegroup consisting of hydrogen, halogen, aromatic hydrocarbon, aliphatichydrocarbon, as well as hydrocarbonoxy radicals which are free of atertiary alpha-carbon atom and halohydrocarbon and halohydrocarbonoxyradicals free of a tertiary alpha-carbon atom and which comprises atleast two carbon atoms between the halogen atom and the phenyl nucleus,and wherein at least one R is hydrogen.
 6. The composition according toclaim 2 wherein the poly(phenylene ether) has a number average molecularweight of between about 4800 and
 12600. 7. The composition according toclaim 2 wherein the poly(phenylene ether) exhibits an intrinsicviscosity (I.V.) of between about 0.3 and 1.0 dl/g when measured in a60/40 weight percent mixture of phenol/tetrchlorathene.
 8. Thecomposition according to claim 2 wherein the polyester is at least onepolyester selected from the group consisting of: poly(alkyleneterephthalate) resins; poly(ethylene terephthalate), poly(butyleneterephthalate), poly(tetramethylene terephthalate), poly(arylterephthalate) and copolymers and/or mixtures thereof.
 9. An articlecomprising the composition of claim 2.